Brain damage is defined as degeneration or death of nerve cells and tracts inside the brain. The rigid casing , the skull, is a special feature of the brain that protects it from many minor outside injuries. Unfortunately any brain abscess, hematoma(large blood clot) following a head injury or brain hemorrhage , and brain tumors creates raised pressure from swelling or hemorrhage that impairs function of the whole brain. If brain cells are destroyed because of injury or disease they cannot be replaced.
Small area damage may have specific effects but because the brain has so many related functions the damage can be varied and numerous.
Some of the more well known defects of the brain are:
Congenital defects due to genetic or chromosomal disorders
Injury heavy blows to head
Infection like encephalitis or meningitis
Tumors like gliomas, meningiomas, acoustic neuromas, and pituitary tumors.
Impaired blood and oxygen supply (hypoxia) and cerebrovascular disease
Degeneration like multiple sclerosis, Alzheimer’s disease
Psychiatric or mental illness
Diffuse damage due to prolonged hypoxia where not enough oxygen reaches the brain. This can occur during a baby’s birth because their brain can only tolerate lack of oxygen for about five minutes. In cardiac arrest where the heart stops or respiratory arrest where cessation of breathing takes place and from poisoning,electrical shock,drowning, or status epilepticus known as prolonged convulsions hypoxia may occur. An accumulation of substances in the brain poisonous to nerve cells such as phenylketonuria or galactosemia causes hypoxia if nit treated early. Damage also occurs when we inhale or ingest environmental pollutants such as lead or mercury.
Localized damage occurs as a result of head injury, stroke, brain tumor, or brain abscess. At birth basal ganglia meaning deep within the brain is caused by bilirubin in great amounts in the infants blood. Bilirubin is formed from destruction of blood cells in hemolytic disease of the newborn. This leads to a condition called kernicterus where movement and mental deficiency take place.
Cerebral palsy characterized by paralysis and abnormal movements and sometimes mental retardation as well as deafness could be caused by brain damage before, during,or after birth. Victims of head injury, stroke, or any other brain damage can be left with many handicaps such as mental handicaps, epileptic seizures, speech handicaps, sensation handicaps, or disturbances of movement.
Nerve cells and tracts in the brain and spinal cord do not recover their functions after they are damaged. However some improvements after brain damage if a victim can learn to use other parts of the brain and other muscle groups of the body. Physical therapy, occupational therapy, and speech therapy as well as teamwork of physicians and specialists can help a person regain as normal a life as possible.